1 Field of the Invention
The present invention relates to a socket for an electric part, and more particularly, to a socket for an electric part for electrically connecting terminals of the electrical part to a printed wiring board of a measurer.
2 Description of the Related Art
In order to carry out the performance test of an electric part such as a semiconductor device or the like, a socket for an electric part for providing an electric connection of terminals of the electric part with an external electric test circuit is conventionally used in many cases.
In such a socket for an electric part, a positioning plate is disposed on a socket body, so that the electric part is placed on the positioning plate. Contact pins are disposed on the socket body, and a slide plate slidable in a horizontal direction is disposed between the positioning plate and the socket body. Further, an operating member for moving the slide plate is disposed for vertical movement relative to the socket body.
In this socket, the slide plate is slid in the horizontal direction through a link mechanism by lowering the operating member, thereby resiliently deforming one of resilient pieces of a contact pin to open upper ends of the resilient pieces. Thereafter, an electric part is placed on the positioning plate, and the operating member is lifted, thereby moving the slide plate back to its original position to release an urging force on the contact pin. This permits the contact pin to be returned to its initial position under its resilient force, whereby the tip ends of the contact pins clamp terminals of the electric part and as a result, the electric connection of the electric part is achieved.
However, such conventional socket for the electric part suffers the following problem: Since the slide plate is slid in the horizontal direction through the link mechanism by lowering the operating member, the mechanism for moving the slide plate is complicated, thereby bringing about an increase in number of components; making it difficult to manufacture the socket; and increasing the manufacture cost.
Another problem is as follows: One of the resilient pieces of the contact pin is opened out, whereby each of the terminals of the electric part is clamped by the resilient pieces, and each of the terminals of the electric part is supported at the two points. For this reason, the stability of contact of the contact pins with the terminals is poor.
Accordingly, it is an object of the present invention to provide a socket for an electric part, in which the slide plate can be moved by a simple structure, and which can be manufactured easily and at a lower cost, wherein the stability of contact of the contact pins with the terminals can be enhanced.
To achieve the above object, according to a first aspect and feature of the present invention, there is provided a socket for an electric part, comprising a plurality of contact pins disposed on a socket body and capable of being brought into and out of contact with terminals of the electric part, and a slide plate disposed on the socket body, so that tip ends of the contact pins are opened and closed to come into and out of contact with the terminals of the electric part by moving the slide plate by an operating member, wherein the slide plate includes contact pin-operating portions provided thereon for opening the contact pins, and operating grooves defined therein and each having a tapered face, and the operating member includes operating arms disposed thereon and adapted to be engaged into the operating grooves in the slide plate, so that the operating arms urge the tapered faces of the operating grooves by urging the operating member downwards, thereby directly moving the slide plate.
With the above arrangement of the first feature, the slide plate is moved directly by urging the tapered faces of the operating grooves by the operating arms by urging the operating member downwards, and the tip ends of the contact pins are opened by the movement of the slide plate. Therefore, the mechanism for moving the slide plate is extremely simple; the number of components can be reduced substantially; and the socket can be manufactured easily and at a lower cost. Further the socket is of such a simple structure that the slide plate is moved by the operating arms of the operating member and the tapered faces of the operating grooves in the slide plate. Therefore, the plurality of operating arms of the operating member and the plurality of operating grooves in the slide plate can be provided easily, whereby the slide plate can be moved stably.
According to a second aspect and feature of the present invention, in addition to the first feature, each of the contact pins is comprised of three resilient pieces: two movable resilient pieces and a single stationary resilient piece, the movable resilient pieces being capable of being opened in such directions that they are spaced apart from each other.
With the above arrangement of the second feature, each of the contact pins is comprised of three resilient pieces: the two movable resilient pieces and the single stationary resilient piece, the movable resilient pieces being capable of being opened in such directions that they are spaced apart from each other. Each of the terminals of the electric part is supported at the three points. Therefore, the stability of contact of the contact pins with the terminals can be enhanced remarkably.
According to a third aspect and feature of the present invention, in addition to the second feature, each of the movable resilient pieces has an inclined guide face formed thereon, and each of the contact pin-operating portions is a :contact pin-operating bore having an inclined face forced therein and adapted to abut against the inclined guide face, so that the movable resilient pieces are opened in a direction perpendicular to a direction of movement of the slide plate by urging the inclined guide face by the contact pin-operating bore by the movement of the slide plate.
With the above arrangement of the third feature, the movable resilient pieces of each of the contact pins are opened in a direction perpendicular to a direction of movement of the slide plate by urging the inclined guide face by the contact pin-operating bore by the movement of the slide plate. Therefore, the movable resilient pieces of each of the contact pins can be opened easily and stably.
The above and other objects, features and advantages of the invention will become apparent from the following description of the preferred embodiment taken in conjunction with the accompanying drawings.